Telegraph system.



J. H. BELL.

TELEGRAPH SYSTEM. APPLICATION FILED Nov.24.1915.

Patented Sept. 26, 1916.

UNITED STATES PATENT oEEIcE.

JOHN H. BELL, 0F EAST ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEGRAPH SYSTEM.

Specification of Letters Patent.

Patented Sept. 26, 1916.

Application led November 24, 1915. Serial No. 63,250.

To all 'whom t may concern.'

Be it known that I, JOHN H. BELL, a subject of the King of Great Britain, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Telegraph Systems, of which the following is a full, clear, concise, and .exact description.

This invention relates to telegraph systems; more particularly to repeatersystems whereby telegraphic signals maybe relayed between two or more stations, and it is particularly applicable for use in` telegraph systems of the so-called double current type rangement is objectionable because of the,

number of expensive polar relays and the complexity of the necessary adjustments, while the second arrangement, in addition to requiring an excessive amount of expensive apparatus, requires the maintenance of very exact resistance and capacity line. balances which, being subject to weather variations, are difficult to obtain andmaintain.

It is, therefore, the principal object of this invention to provide a system which is at the same time highly efficient and, because of the reduction of expensive partsand difficult adjustments, cheaper and simpler than the systems now in common use.

The invention is applicable not only to single repeater systems, but is highly advantageous also for both forked and multiple repeater systems.

lTo these ends the invention, inaccordance with its general characteristics, comprises an electromagnetically actuated device, such, for example, as a polarized relay, responsive to current impulses in onel section of a transmission line for controlling the application and character of current impulses vimparted to another section or sections of such line, together with a slo-w release electromagnetically actuated device for associating with a corresponding section or sections of the line. l'

The above and other objects of the invention will be fully set forth in the following description andv claims, and will be more readily understood by reference to the accompanying drawing, wherein- Figure l shows. dia rammatically the preferred arrangement o circuits and lapparatus at the terminal stations, and Figs. 2, 3 and i are diagrams of the connections for single, forked and multiple repeater systems respectively.

At the so-called terminal stations of the transmission lines, the character of the current impulses imparted theretois governed by; a transmitting relay 10, whose armature 11 is adapted to engage back and front contacts connected respectively to the negative and positive terminals of a source ofenergy, as indicated in Fig. 1. The incoming irn-4 pulses from the line pass through the windings of a polarized line relay 12, whose armature 13 is connected toa grounded source of energy 14. Armature 13 coperates with a contactconnected by a conductorl to one vterminal of a sounder 16, which may be located at .the terminal station or removed to a nearby subscribers station R, as shown in Fig. 1. Also at the subscribers'station and connected to the terminal station by a conductor 20 are a telegraph key-21 and a transmitting sounder 22 which may be of the usual well-known constructions. At the vand disassociating the first mentioned device j terminal station a telegraph key 23 may A also be joined to conductor 20. If there is no sbscribers station, key 2l and Sounders 16 and 22 may be` located at the terminal station, and `key 23 may be dispensed with. Conductor 20 is connected to one terminal of a vrelay 24, the other terminal of which isjoined to a 'terminal of relay 10, whose winding is also connected to a grounded source of energy 25. Relay 21 has an armature 26 connected to the line and cooperating with back and front contacts, respectively joined to the winding of relay 12'and armature 11 of relay 10. Relay 24 is vva slow vrelease relay, whose adjustment should be such that while its armature is readily'attracted against its front contact, it is ,not released therefrom during the intervals between current impulses Which go to make up letter or.

character signal combinations of a dot and dash code, such as the Morse code. Between such combinations, however, as between words, the intervals are preferably of sutlicient length to allow the armature of relay 24 to be completely retracted.

When key 21 or key 23 is depressed to start the signals, the flow of current through relays 24 and 10 cause them to attract their armatures 26 and 11 respectively. Armature 26 removes the line connection from relay 12-to armature 11, while armature 11 moves against its front contact. Current of positive potential is thereupon impressed upon the line. During the intervals between dots and dashes, armature 11 engages its back contact and negative c'urrent passes to the line, since, as hereinbefore explained, armature 26 of relay 24 does not leave its front contact during these relatively short intervals between the impulses of a letter or character combination. Relay 10, therefore, follows the manipulations of the telegraph keys, and imparts to the line positive and negative currents to represent the dots and dashes and spaces of the code employed. Relay 24, however, does not follow these manipulations, pulling up its armature on the first closure of a key and holding the armature in this condition until a key has been open a sufficient length of time to allow it to fall back. `When armature 26 is against its back contact, current impulses in the line may operate the line relay 12 to control the action of the sounder 16.

Referring now to Fig. 2, the transmission line is shown in two sections, 1 and 2, leading to terminal stations or other repeater ,sets,.and between which a repeater set arranged in accordance With this invention is located. lVith each section of the line there is associated a polarized relay and a slow release relay, as will be hereinafter eX- plained. For the convenience of the repeater operator, each line section is also shown provided with a. key and sounder, although this apparatus ma-y be dispensed with if desired. Thus, line section 1 passes to a lever 30of a. key K and line section 2 passes to a lever 30 of a key K". Levers 30 of keys K and K coperate with right-hand and left-hand contacts connected to opposite poles of sources of energy 32 and 33 respectively. Keys K and K are also provided, in

the usual manner, with switches 34, which normally close circuits around the key levers 30 as shown by the full lines but which, when the. corresponding key is to be manipulated, may be either separately or automatically opeated by key lever controlled mechanism to break the normal circuit and transfer the corresponding line section to the key lever, as shown by the dotted lines. Keys of each type are well known in the art and need no description. The relays under the control of current impulses in line section 1- are a non-polarized relay 40 and a polarized relay 41, and the relays under the control of current impulses in line section 2 are a nonpolarized relay 42 and a polarized relay 43. .Relays 40 and 42 are slow release, attracting their armatures readily but not allowing them to leave their front contacts during the low magnetic intervals occurring between the dot and dash and space current intervals. The longer no-current intervals between words, however, are 1sufficient to cause the retraction of the armatures of relays 40 and 42. I

Polarized relay 41 is provided with an armature 45 connected lto a front'contact co operating with an armature 46 of relay 40 and, if desired, to a grounded polarized sounder 47. Armature 45 is located between and in its alternate positions engages right-hand and left-hand contacts,'respec tively connected to the positive and negative poles of source 33. In a like manner, an armature 55 of relay 43 is connected to a front contact coperating with an armature 56 of relay 42 and a polarized sounder 57, and coperates with right-hand and lefthand contacts connected'respectively to the` positive and negative poles of source 32.

If it is not desired that the repeater operator hear the signals being repeated, the sounders may be dispensed with. Line 'section 1 is normally extended through switch 34 of key K, armature 56 and its back contact through the windings of relays 40 and 41 to ground, while line section 2 extends through switch 34 of key K', armature 46 and its back contact through the windings of relays 42 and 43 to ground. Vh'en, however, relay 40 is energized by current impulses arriving over line section 1, the path for section 2 from armature 46 through'the windings of relays 42 and 43 zis broken and a circuit is completed through the front contact of relay 40 to the armature of relay 41.`

In this condition current of a character determined by the action of polar relay,41 is impressed upon line section 2. The opening of the circuit from armature 46 through the windings of relays 42 and 43 removes what would otherwise be a path in parallel with line section 2. In a similar manner, when relay 42 is energized by current impulses arriving over line section 2, the path for section 1 from armature 56 through the Windings of relays 40 and 41 is interrupted and a circuit is. completed from its front contact to the armature of relay 43, so that currents controlled by the position of armature 56 are impressed upon line section 1. lVhen, therefore, a train of positive and negative impulses comes in from a distant station over line section 1, both relays 40 and 41 are energized. Armature-46 of relay 40 associates armature 45 of relay 41 with line however, armature 46 falls back and the repeater is at normal. In a like manner, signals arriving from line section 2 are repeated `from source 3;). to section 1, the character of such repeated impulses being determined by polarized relay 43.

In the forked repeater shown in Fig. 3, current impulses arriving over line section 1 operate a non-polarized slow-release relay G0 and a polarized relay (il. An armature 62 ot' relay 61 cooperates with contacts connected to the poles of a suitable source of energy 63 and is connected to a pair ot' front contacts associated with armatures G4 and (35 of relay 60. In a similar manner, line section 2 is associated with a noli-polarized slow-release relay having a pair of armatures 71 and 75, and with a polarized relay 71 having an armature 7:2 controlling the application of current from a source of energy 73; and line section 3 is associated with a non-polarized slow-release relay 80 equipped with armatures 8l and S5, and with a polarized relay S1 provided with an armature 82 controlling the application of current from a source of energy 83,.

IVhen signal current im ulses arrive over line section 1, they pass, y way of armature S1 and the cooperating back contact of relay 80, and armature 7 -l and the coperating back contact of relay 70, through relays `G0 and 61. .The first impulse ot' a combination causes both relays 60 and 61l to operate, relay G0 connecting armature 62 to line section 2 through armatures 65 and 85, and to line section 3 through armatures G1 and 7 5, while relay 61 causes its armature 62 to-connect with the proper pole of source G3. Relay 61 follows the subsequent impulses of the combination, sothat the currents over section 1 are relayed to sections 2 and 3 from source G3, since relay 60 does not allow its armatures to disengage their front contacts until during the comparatively longintervals between words. In like manner, impulses arriving over line section 2 are relayed to line sections 1 and 3 from source 73 through theagency of relays 70 and 71, and impulses arriving over line section 3 are relayed to line sections 1 and 2 from source 83 through the agency of relays 80 and 81. To avoid confusion, no repeater operators keys or Sounders are shown in connection with this circuit, but such apparatus may beadded, when desired, in exactly the same manner as shown in Fig. 2.

In the multiple repeater, to avoid a multiplicity of contacts on the lion-polarized slow release relays, two extra relays for each line section are employed. Thus, referring to Fig. -l, it will be noted that line section 1 is associated with a non-polarized slow-release relay 90 and a polarized relay 91, as in the single and forked repeaters. In addition, there is a current control or transmitting relay 92y and a slow release line or section control relay 93. Slow release relay 90 is provided with a pair of armatures 91 and 95, and polarized relay 91 is provided with an armature 96 cooperating with a contact connected to a grounded source of energy 97.

Relay 92 is provided with an armature 9S cooperating with back and front contacts connected respectively to the negative and positive poles of a suitable source of energy, as shown, while relay 93 is provided with an armature 99 connected to line section 1 and cooperating with a front contact connected to armature 98 and a back contact connected to a circuit through the windings yot' relays and 91. The other line sections are associated with'relays in a similar manner. For section '2V there is `a neutral slow-release relay 100 provided'with armatures 101 and 102, a polarized relay 103 having an armature 104; adapted to cooperate with a source of energy 105, a transmitting relay 10G having an armature 107, anda line control relay 103 provided with an armature 109.

A sufficient understanding of the multiple repeater system may be obtained from a description of its operation, which is as follows: Assuming that a ,character combination of impulses is arriving over line sec-v tion 1, the first such impulse will pass- 'through armature 99 and the windings ot relays 90 and 91. 'Relay 90 attracts its armatures 9-1 and 95, armature 94 preparing a. circuit from armature 96 through the fronti 'release'relav 121, windings of a -relav 122 and a neutral slow-release relay 1'23, back contact and armature 191 off relay 121, armature 130 and back contact of a neutral slow-release relay 131 and the windings of a relay 132, and a neutral slow-release relay 133 through the back contact and armature 131 ot' relay 131 to armature 95 of relay 90v Thiscircuit is grounded at one end through the front contact coperating with armature 95, and at the other end through grounded source of energy 9T by armature 90. Current tiows in this circuitand relays 100, 108, 112, 113, 122, 123, 132 and 133 pull up their armatures. The armatures of relays 108, 113, 123 and 133 respectively connect line sections 2, 3, -l and 5 with armatures 107, 135, 136 and 13T of transmitting relays 100, 112, 122 and 132, and since these relays are also energized, as hereinbefore explained, a positive current Hows over line sections 2, 3, 1 and This current flows` until a reversal in line section 1 auses armatiii'e 96 of relay 91 to become disengaged from association with source 9T, whereupon relays 106, 112. 122 and 132 are denergized and their armatures fall back, causing negative current to pass over their respective sections, since, as in the case of the single and forked repeaters. the slow-release relays 90, 10S, 113, 123 and 133 do not allow their armatures to leave their eoperating t'roiit contacts during the low magnetic intervals during current reversals or the intervals between the impulses making up a word. Subsequent impulses arriving over line section 1 are followed by armature 0o otl .relay 91, which, by opening and closing the hereinbefore traced circuit through transmitting relays 106, 112, 122 and 132, causes currents of the proper duration and polarity to be impressed upon line sections 2. 3. -l and During the longer intervals between words. however, slow-release relays 00, 108. 113. 123 and 132 allow their armatures to tall back and the repeater is again at normal.

1n a similar manner, impulses arriving over line section 2 are repeated over line sections 1, 3, 4 and 5, the circuit through the various relays being grounded through the front contact of armature 102 and connected to source 105 at Athe proper times by armature 10-1 ot' polarized relay 103. The same is true ot impulses arriving over line section 3, which are repeated to line sections 1, 2. 4. Although several sources oi Curi'ent have, for convenience. been shown in the drawing it will he understood that each one of the correspondingly poled sources may he and preferably are one and the same current source.

The invention claimed is:

1. ,1n a telegraph repeating system. sources of current therefor. a plurality of line relay groups, a telegraph line circuit for each group.'and contacts operated by the relays ot' any group to include said sources ot' .current to repeat telegraphic signals into tions, an electromagneticaily-actuated device associated with each said section and controlling the character oic signal current impulses imparted to other ot' said sections, and a slow release electr()magnetically-actuated device tor each said section acting when in operation to associate another said section with a corresponding one of said first mentioned devices and disassociate the other said section and the other said slow rel aise device.

3. A telegraph system comprising a transmission liiie divided into sections. a polarized relay adapted to he associated with each ot said sections and controlled hy current impulses traversing a corresponding section to control the character ot current impulses in another section, and a non-polarized slowrelease relay t'or each said section acting to associate the polarized relay ot' a corresponding section with another said section and to disassociate other raid polarized and slowrelease relays from their corresponding sections.

4. A telegraph system comprising a transmission line divided into sections. a polarized relay adapted to he associated with each of said sections and controlled by current impulses therein to determine the character ot' current impulses in other sections. and a slow-release relay t'or each said section acting to associate the polarized relay ot' a corresponding,r section with other sections and to disassociate other said polarized and slow-release relays from their corresponding sections.

5. In a telegraph repeating system. a plurality of line relay groups. a telegraph line circuit tor each group. and contacts` operated hy a relay in any ont` of the groups to disable the. relays ot' the other groups.

In a telegraph repeating system. a phirality ot line relay groups. a telegraph line circuit for each group. and contacts operated hy a relay in any group to ljoin the line circuits ot' the other groups one with another.

T. ln a telegraph repeating systennsources of current therefor. a plurality of line relay groups. each comprising a slow release relay and a polarized rel-ay. a telegraph line circuit for each group. contacts operated by the slow release relay ot' any group when active to disable the relays oic the other` groups and to join the line circuits of the other relay groups one with another. and contacts operated by the polarized relay of. the active group for including said sources ot'` current to repeat telegraphic signals into the joined line circuits.

In witness whereof I hereunto subscribe my iiaiue this 20th day ot' November, A. D. 1915.

JOHN ll. BELL; 

